diff --git a/config.h b/config.h
index de7d50d..1fe461f 100644
--- a/config.h
+++ b/config.h
@@ -1,7 +1,7 @@
 #ifndef CONFIG
 #define CONFIG
 
-#define VERSION             149
+#define VERSION             150
 
 //try to keep this in sync.
 //SavvyCAN will complain if you connect a GVRET board with a revision
diff --git a/fuzzingwindow.cpp b/fuzzingwindow.cpp
index f038269..77bbe06 100644
--- a/fuzzingwindow.cpp
+++ b/fuzzingwindow.cpp
@@ -1,17 +1,203 @@
 #include "fuzzingwindow.h"
 #include "ui_fuzzingwindow.h"
+#include "utility.h"
+#include <QDebug>
 
-FuzzingWindow::FuzzingWindow(const QVector<CANFrame> *frames, SerialWorker *worker, QWidget *parent) :
+FuzzingWindow::FuzzingWindow(const QVector<CANFrame> *frames, QWidget *parent) :
     QDialog(parent),
     ui(new Ui::FuzzingWindow)
 {
     ui->setupUi(this);
 
     modelFrames = frames;
-    serialWorker = worker;
+
+    fuzzTimer = new QTimer();
+
+    connect(ui->btnStartStop, &QPushButton::clicked, this, &FuzzingWindow::toggleFuzzing);
+    connect(ui->btnAllFilters, &QPushButton::clicked, this, &FuzzingWindow::setAllFilters);
+    connect(ui->btnNoFilters, &QPushButton::clicked, this, &FuzzingWindow::clearAllFilters);
+    connect(fuzzTimer, &QTimer::timeout, this, &FuzzingWindow::timerTriggered);
+    connect(ui->spinTiming, SIGNAL(valueChanged(int)), this, SLOT(changePlaybackSpeed(int)));
+    connect(ui->listID, &QListWidget::itemChanged, this, &FuzzingWindow::idListChanged);
+
+    refreshIDList();
+
+    currentlyFuzzing = false;
 }
 
 FuzzingWindow::~FuzzingWindow()
 {
     delete ui;
 }
+
+void FuzzingWindow::changePlaybackSpeed(int newSpeed)
+{
+    fuzzTimer->setInterval(newSpeed);
+}
+
+void FuzzingWindow::timerTriggered()
+{
+    CANFrame thisFrame;
+    sendingBuffer.clear();
+    for (int count = 0; count < ui->spinBurst->value(); count++)
+    {
+        thisFrame.ID = currentID;
+        for (int i = 0; i < 8; i++) thisFrame.data[i] = currentBytes[i];
+        if (currentID > 0x7FF) thisFrame.extended = true;
+        else thisFrame.extended = false;
+        thisFrame.bus = 0; //hard coded for now. TODO: do not hard code
+        thisFrame.len = 8;
+        sendingBuffer.append(thisFrame);
+        calcNextID();
+        calcNextBitPattern();
+        numSentFrames++;
+    }
+    emit sendFrameBatch(&sendingBuffer);
+    ui->lblNumFrames->setText("# of sent frames: " + QString::number(numSentFrames));
+}
+
+void FuzzingWindow::clearAllFilters()
+{
+    for (int i = 0; i < ui->listID->count(); i++)
+    {
+        ui->listID->item(i)->setCheckState(Qt::Unchecked);
+    }
+}
+
+void FuzzingWindow::setAllFilters()
+{
+    for (int i = 0; i < ui->listID->count(); i++)
+    {
+        ui->listID->item(i)->setCheckState(Qt::Checked);
+    }
+}
+
+void FuzzingWindow::calcNextID()
+{
+    if (seqIDScan)
+    {
+        currentID++;
+        if (rangeIDSelect)
+        {
+            if (currentID > endID) currentID = startID;
+        }
+        else //IDs by filter. So, select the first filter
+        {
+            if (currentID > selectedIDs.length()) currentID = 0;
+        }
+    }
+    else //random IDs
+    {
+        if (rangeIDSelect)
+        {
+            int range = endID - startID;
+            currentID = startID + qrand() % range;
+        }
+        else //IDs by filter so pick a random selected ID from the filter list
+        {
+            currentID = qrand() % selectedIDs.length();
+        }
+    }
+}
+
+void FuzzingWindow::calcNextBitPattern()
+{
+    //simple, quick random data for now
+    for (int i = 0; i < 8; i++)
+    {
+        currentBytes[i] = qrand() % 256;
+    }
+}
+
+void FuzzingWindow::toggleFuzzing()
+{
+    if (currentlyFuzzing) //stop it then
+    {
+        ui->btnStartStop->setText("Start Fuzzing");
+        currentlyFuzzing = false;
+        fuzzTimer->stop();
+    }
+    else //start it then
+    {
+        ui->btnStartStop->setText("Stop Fuzzing");
+        currentlyFuzzing = true;
+
+        startID = Utility::ParseStringToNum(ui->txtStartID->text());
+        endID = Utility::ParseStringToNum(ui->txtEndID->text());
+
+        seqIDScan = ui->rbSequentialID->isChecked();
+        rangeIDSelect = ui->rbRangeIDSel->isChecked();
+        seqBitSelect = ui->rbSequentialBits->isChecked();
+
+        numSentFrames = 0;
+
+        if (seqIDScan)
+        {
+            if (rangeIDSelect)
+            {
+                currentID = startID;
+            }
+            else //IDs by filter. So, select the first filter
+            {
+                currentID = 0;
+            }
+        }
+        else //random IDs
+        {
+            if (rangeIDSelect)
+            {
+                int range = endID - startID;
+                currentID = startID + qrand() % range;
+            }
+            else //IDs by filter so pick a random selected ID from the filter list
+            {
+                currentID = qrand() % selectedIDs.length();
+            }
+        }
+
+        calcNextBitPattern();
+
+        fuzzTimer->start();
+    }
+}
+
+void FuzzingWindow::refreshIDList()
+{
+    ui->listID->clear();
+
+    int id;
+    for (int i = 0; i < modelFrames->count(); i++)
+    {
+        id = modelFrames->at(i).ID;
+        if (!foundIDs.contains(id))
+        {
+            foundIDs.append(id);
+            selectedIDs.append(id);
+            QListWidgetItem *thisItem = new QListWidgetItem();
+            thisItem->setText(Utility::formatNumber(id));
+            thisItem->setFlags(thisItem->flags() | Qt::ItemIsUserCheckable);
+            thisItem->setCheckState(Qt::Checked);
+            ui->listID->addItem(thisItem);
+        }
+    }
+    //default is to sort in ascending order
+    ui->listID->sortItems();
+}
+
+void FuzzingWindow::idListChanged(QListWidgetItem *item)
+{
+    int id = Utility::ParseStringToNum(item->text());
+    if (item->checkState() == Qt::Checked)
+    {
+        if (!selectedIDs.contains(id))
+        {
+            qDebug() << "adding " << id << " to list of selected IDs";
+            selectedIDs.append(id);
+        }
+    }
+    else
+    {
+        qDebug() << "removing " << id << " from the list of selected ids";
+        selectedIDs.removeOne(id);
+    }
+}
diff --git a/fuzzingwindow.h b/fuzzingwindow.h
index 2e13882..fe88dab 100644
--- a/fuzzingwindow.h
+++ b/fuzzingwindow.h
@@ -2,8 +2,9 @@
 #define FUZZINGWINDOW_H
 
 #include <QDialog>
+#include <QListWidget>
+#include <QTimer>
 #include "can_structs.h"
-#include "serialworker.h"
 
 namespace Ui {
 class FuzzingWindow;
@@ -14,14 +15,38 @@ class FuzzingWindow : public QDialog
     Q_OBJECT
 
 public:
-    explicit FuzzingWindow(const QVector<CANFrame> *frames, SerialWorker *worker, QWidget *parent = 0);
+    explicit FuzzingWindow(const QVector<CANFrame> *frames, QWidget *parent = 0);
     ~FuzzingWindow();
 
+signals:
+    void sendCANFrame(const CANFrame *, int);
+    void sendFrameBatch(const QList<CANFrame> *);
+
+private slots:
+    void changePlaybackSpeed(int newSpeed);
+    void timerTriggered();
+    void clearAllFilters();
+    void setAllFilters();
+    void toggleFuzzing();
+    void idListChanged(QListWidgetItem *item);
+
 private:
     Ui::FuzzingWindow *ui;
     const QVector<CANFrame> *modelFrames;
     QTimer *fuzzTimer;
-    SerialWorker *serialWorker;
+    QList<int> foundIDs;
+    QList<int> selectedIDs;
+    QList<CANFrame> sendingBuffer;
+    int startID, endID, currentID;
+    bool seqIDScan, rangeIDSelect, seqBitSelect;
+    bool currentlyFuzzing;
+    uint8_t currentBytes[8];
+    uint8_t bitGrid[64];
+    int numSentFrames;
+
+    void refreshIDList();
+    void calcNextID();
+    void calcNextBitPattern();
 };
 
 #endif // FUZZINGWINDOW_H
diff --git a/fuzzingwindow.ui b/fuzzingwindow.ui
index 943e5a1..43bf9ab 100644
--- a/fuzzingwindow.ui
+++ b/fuzzingwindow.ui
@@ -13,7 +13,7 @@
   <property name="windowTitle">
    <string>Fuzzing Window</string>
   </property>
-  <layout class="QVBoxLayout" name="verticalLayout" stretch="1,1,3,6">
+  <layout class="QVBoxLayout" name="verticalLayout" stretch="1,1,3,6,0,0">
    <item>
     <layout class="QHBoxLayout" name="horizontalLayout">
      <item>
@@ -21,12 +21,19 @@
        <item>
         <widget class="QLabel" name="label">
          <property name="text">
-          <string>Interframe Timing</string>
+          <string>Interframe Timing (ms)</string>
          </property>
         </widget>
        </item>
        <item>
-        <widget class="QSpinBox" name="spinBox"/>
+        <widget class="QSpinBox" name="spinTiming">
+         <property name="maximum">
+          <number>10000</number>
+         </property>
+         <property name="value">
+          <number>10</number>
+         </property>
+        </widget>
        </item>
       </layout>
      </item>
@@ -40,7 +47,17 @@
         </widget>
        </item>
        <item>
-        <widget class="QSpinBox" name="spinBox_2"/>
+        <widget class="QSpinBox" name="spinBurst">
+         <property name="minimum">
+          <number>1</number>
+         </property>
+         <property name="maximum">
+          <number>10</number>
+         </property>
+         <property name="value">
+          <number>1</number>
+         </property>
+        </widget>
        </item>
       </layout>
      </item>
@@ -53,19 +70,25 @@
        <property name="title">
         <string>ID Scanning</string>
        </property>
+       <property name="alignment">
+        <set>Qt::AlignLeading|Qt::AlignLeft|Qt::AlignVCenter</set>
+       </property>
        <layout class="QHBoxLayout" name="horizontalLayout_3">
         <item>
-         <widget class="QRadioButton" name="radioButton_2">
+         <widget class="QRadioButton" name="rbSequentialID">
           <property name="text">
            <string>Seqential</string>
           </property>
          </widget>
         </item>
         <item>
-         <widget class="QRadioButton" name="radioButton">
+         <widget class="QRadioButton" name="rbRandomID">
           <property name="text">
            <string>Random</string>
           </property>
+          <property name="checked">
+           <bool>true</bool>
+          </property>
          </widget>
         </item>
        </layout>
@@ -78,14 +101,17 @@
        </property>
        <layout class="QHBoxLayout" name="horizontalLayout_4">
         <item>
-         <widget class="QRadioButton" name="radioButton_3">
+         <widget class="QRadioButton" name="rbRangeIDSel">
           <property name="text">
            <string>Range of IDs</string>
           </property>
+          <property name="checked">
+           <bool>true</bool>
+          </property>
          </widget>
         </item>
         <item>
-         <widget class="QRadioButton" name="radioButton_4">
+         <widget class="QRadioButton" name="rbFilterIDSel">
           <property name="text">
            <string>Filter List</string>
           </property>
@@ -101,17 +127,20 @@
        </property>
        <layout class="QHBoxLayout" name="horizontalLayout_8">
         <item>
-         <widget class="QRadioButton" name="radioButton_5">
+         <widget class="QRadioButton" name="rbSequentialBits">
           <property name="text">
            <string>Sequential</string>
           </property>
          </widget>
         </item>
         <item>
-         <widget class="QRadioButton" name="radioButton_6">
+         <widget class="QRadioButton" name="rbRandomBits">
           <property name="text">
            <string>Random</string>
           </property>
+          <property name="checked">
+           <bool>true</bool>
+          </property>
          </widget>
         </item>
        </layout>
@@ -137,7 +166,7 @@
            </widget>
           </item>
           <item>
-           <widget class="QLineEdit" name="lineEdit"/>
+           <widget class="QLineEdit" name="txtStartID"/>
           </item>
          </layout>
         </item>
@@ -151,7 +180,7 @@
            </widget>
           </item>
           <item>
-           <widget class="QLineEdit" name="lineEdit_2"/>
+           <widget class="QLineEdit" name="txtEndID"/>
           </item>
          </layout>
         </item>
@@ -161,19 +190,19 @@
      <item>
       <layout class="QVBoxLayout" name="verticalLayout_6">
        <item>
-        <widget class="QListWidget" name="listWidget"/>
+        <widget class="QListWidget" name="listID"/>
        </item>
        <item>
         <layout class="QHBoxLayout" name="horizontalLayout_9">
          <item>
-          <widget class="QPushButton" name="pushButton">
+          <widget class="QPushButton" name="btnAllFilters">
            <property name="text">
             <string>All</string>
            </property>
           </widget>
          </item>
          <item>
-          <widget class="QPushButton" name="pushButton_2">
+          <widget class="QPushButton" name="btnNoFilters">
            <property name="text">
             <string>None</string>
            </property>
@@ -195,6 +224,27 @@
      </property>
     </widget>
    </item>
+   <item>
+    <widget class="QPushButton" name="btnStartStop">
+     <property name="text">
+      <string>Start Fuzzing</string>
+     </property>
+    </widget>
+   </item>
+   <item>
+    <widget class="QLabel" name="lblNumFrames">
+     <property name="font">
+      <font>
+       <pointsize>11</pointsize>
+       <weight>75</weight>
+       <bold>true</bold>
+      </font>
+     </property>
+     <property name="text">
+      <string># of sent frames:</string>
+     </property>
+    </widget>
+   </item>
   </layout>
  </widget>
  <customwidgets>
diff --git a/mainwindow.cpp b/mainwindow.cpp
index fe94de8..078ae66 100644
--- a/mainwindow.cpp
+++ b/mainwindow.cpp
@@ -923,7 +923,9 @@ void MainWindow::showFuzzingWindow()
 {
     if (!fuzzingWindow)
     {
-        fuzzingWindow = new FuzzingWindow(model->getListReference(), worker);
+        fuzzingWindow = new FuzzingWindow(model->getListReference());
+        connect(fuzzingWindow, SIGNAL(sendCANFrame(const CANFrame*,int)), worker, SLOT(sendFrame(const CANFrame*,int)));
+        connect(fuzzingWindow, SIGNAL(sendFrameBatch(const QList<CANFrame>*)), worker, SLOT(sendFrameBatch(const QList<CANFrame>*)));
     }
     fuzzingWindow->show();
 }
diff --git a/serialworker.cpp b/serialworker.cpp
index d6d695d..d6f212b 100644
--- a/serialworker.cpp
+++ b/serialworker.cpp
@@ -193,8 +193,10 @@ void SerialWorker::sendFrame(const CANFrame *frame, int bus = 0)
 //Don't get carried away here. The GVRET firmware only has finite
 //buffers and besides, the other end will get buried in traffic.
 void SerialWorker::sendFrameBatch(const QList<CANFrame> *frames)
-{    
+{
+    sendBulkMutex.lock();
     for (int i = 0; i < frames->length(); i++) sendFrame(&frames->at(i), frames->at(i).bus);
+    sendBulkMutex.unlock();
 }
 
 void SerialWorker::updateBaudRates(int Speed1, int Speed2)
diff --git a/serialworker.h b/serialworker.h
index 0741fab..2b71266 100644
--- a/serialworker.h
+++ b/serialworker.h
@@ -76,6 +76,7 @@ private:
     CANFrameModel *canModel;
     QTimer *ticker;
     QTime *elapsedTime;
+    QMutex sendBulkMutex;
     int framesPerSec;
     int gotFrames;
     int targetID;